How to add JPanel to JScrollPane?

Question

I have added one JPanel to the JScrollPane. But the main panel is not scrolling. My problem is like this:

JPanel MainPanel = new JPanel();
MainPanel.setBounds(width/2,height/10,width/5,height/5);
MainPanel.setLayout(null);

JScrollPane scrollPane= new JScrollPane(MainPanel);
scrollPane.setBounds(width/2,height/10,width/5,height/5);
//Added scrollPane to MainFrame Panel
MainFrame.add(scrollPane);

//Added four JPanel to MainPanel
JPanel subPanel1 = new JPanel();
subPanel.setbounds(10,20,50,50);
MainPanel.add(subPanel);

JPanel subPanel2 = new JPanel();
subPanel2.setbounds(50,60,50,50);
MainPanel.add(subPanel2);

JPanel subPanel3 = new JPanel();
subPanel3.setbounds(50,100,50,50);
MainPanel.add(subPanel3);

JPanel subPanel4 = new JPanel();
subPanel4.setbounds(50,60,50,50);
MainPanel.add(subPanel4);

I didn't see the subPanel3 and subPanel4. Now I'm able to see the vertical scroll bar but it is not working.

Using `setBounds()` aloing with `setLayout(null)` you're basically setting the size of your main panel which happens to be the size of the scrollpane - so there is nothing to scroll. — Thomas, Apr 01 '19 at 10:16
@Thomas I remove the setBound() but still, I'm not able to see the subPanel3 and 4 . — Harshad201, Apr 01 '19 at 10:21
*"I remove the setBound()"* Remove the `null` layout then [edit] to show a [mcve] of the change code. — Andrew Thompson, Apr 01 '19 at 10:26
As an aside, add at least one label to each panel, otherwise the preferred size will be 0 x 0. — Andrew Thompson, Apr 01 '19 at 10:31
Thank you @Thomas it works when I removed the setBound() and setLayout(null) from MainPanel. — Harshad201, Apr 01 '19 at 11:05

score 0 · Answer 1 · answered Apr 01 '19 at 10:27

0

I recommend you to use layouts instead of setBounds(). GridBagLayout, GridLayout, FlowLayout, BoxLayout and BorderLayout will be useful. Documentation is here: https://docs.oracle.com/javase/tutorial/uiswing/layout/visual.html

And append this at the bottom of the code:

scrollPane.getViewport().setView(MainPanel);

answered Apr 01 '19 at 10:27

stftnk

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3

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`scrollPane.getViewport().setView(MainPanel);` is not necessary, given `JScrollPane scrollPane= new JScrollPane(MainPanel);` (the panel is passed in the constructor and will be added to the viewport). – Andrew Thompson Apr 01 '19 at 10:29

How to add JPanel to JScrollPane?

1 Answers1